Kohlberg Kravis Roberts has hired the former CEO of insurance brokerage Willis Group.

Joseph Plumeri was named a senior adviser to the private-equity firm and will join the board of directors at First Data Corp., a credit-card processing company owned by KKR. Plumeri worked with First Data CEO Frank Bisignano at Citigroup.

"Joe Plumeri is a leader known to be a catalyst for positive change," KKR co-founder Henry Kravis said. "He will be an asset to KKR as a senior adviser and I look forward to working with him again both at the firm and on the First Data board."